Question

Determine which of the observations below are testable. For those that are testable:

·         Determine if the observation is qualitative or quantitative.

·         Write a hypothesis and a null hypothesis.

·         What is your experimental approach?

·         What are the dependent and independent variables?

·         What are your controls, both positive and negative?

·         How will you collect your data?

·         How will you present your data (e.g., chart, graph, type)?

·         How will you analyze your data?

Observations

1.    A plant grows three inches faster per day when placed on a window sill than it does when placed on a coffee table in the middle of the living room.

Quantitative

2.    The bank teller with brown hair and brown eyes is taller than the other tellers.

Null Hypothesis

3.    When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she eats fatty foods and does not exercise.

4.    The Italian restaurant across the street closes at 9 pm, but the one two blocks away closes at 10 pm.

5.    For the past two days, the clouds have come out at 3 pm, and it has started raining at 3:15 pm.

6.    George did not sleep at all the night following the start of Daylight Savings Time.

Answer 1

The observations that are testable are 1, 2 and 3.

1) The plant grows three inches taller when placed on a window sill than when it is placed on the coffee table in the middle of the room. This is a quantitative variable because the height of the plant can be measured.

Hypothesis: Plants placed near window grows faster than those plants placed in the middle of the room.

Null hypothesis: There is no difference in growth of plants placed near window or middle of the room.

The experiment can be done by measuring the height of plants placed near window or center of the room. The dependent variable is the height or growth of the plant and the independent variables are the amount of water, fertiliser, sunlight etc. The control includes the plants placed in the dark.

The data collected is the height of plants measured over a few days. The data can be presented by means of tables. It can also be represented in the form of scatter plot or bar diagram.

The data can be analysed by using unpaired t test which compared the mean and standard deviation of height of plants between the two groups. If the p value calculated is found to be less than 0.05, there is significant difference in height between the two groups. So, Null hypothesis is rejected and alternate hypothesis is accepted.